Role of planetary winds in planet evolution and population

Abstract The role of atmospheric evaporation in shaping exoplanet populations remains a major unsolved problem in the literature. Observational evidence, like the bimodal distribution of exoplanet radii, suggests a catastrophic past in which exoplanets with masses of approximately 1–10M⊕ often lose their primordial envelopes and experience a drastic reduction in their radii. Our knowledge of the mechanisms behind atmospheric evaporation remains nebulous, with new models regularly introduced in the literature. Understanding the principles behind these models and knowing when to apply them is essential for constraining how planets evolve. This communication reviews the mechanisms behind atmospheric evaporation by exploring observations and theory, as well as introducing some of the principles in the forthcoming paper Modirrousta-Galian & Korenaga (in press).